Milking-machine pulsator



- R. B. FORS-YTH.

MLKING MACHINE PULSTOR.

APPLICATION FILED IAN. 4. |922.

1,420,421. Patented June 20,1922.A

Unire-1.a arras ROBERT BRUCE roiasnffrrr7 on cHaIsTcHUacn, New ZEALAND,

MILKING-MACHINE PULSATOR.

Specification of Lettersllateiit. Patented une3 2Q, 192.2'

Application inea January 4,1922. serial No.' 526,972.

To all ywhom t may concern:

Be it known that I, ROBERT BRUCE FonsYTH, a subject of the King. of Great Britain, residingat Christchurch, New Zealand, have invented new and useful mprovements in and Relating to Milking-Machine Pulsators, of which the following. is a specifica tion.

This invention relates to pulsators for milking machines and refers to the particu.- lar form of pulsator which is adapted to operate in response to a primary pulsation and when so operatedy to produce a secondary pulsation.

In a pulsation of this nature it is however impossible to provide eflicient lubrication for the moving parts, the result being7 in the case of the constructions hitherto employed. that the efficiency of the device has gradually declined in consequence of wear of such parts.

It is the object of the present invention therefore to provide a simple and novel construction whereby the full effect of the primary pulsation will be secured and the above mentioned trouble. due to wear. of the working parts, avoided.

In carrying this object into effect the present invention comprises a cylinder or valvehousing within which is adapted to reciprocate a piston or operable valve-member. The said cylinder is formed around its interior with peripheral shoulders arranged in pairs of which the individual shoulders are in opposed relation to each other.

rhound the periphery of the piston also are formed peripheral shoulders likewise arranged in pairs to correspond with those of the cylinder and with which they are adapted to come into and out of abutment as the piston reciprocates.

Arranged to enter the cylindcrat points between the two shoulders of the latter constituting the pair or each pair are ports connecting with the pulsation chambers of the neat-cups or other portions of the plant to which the secondary pulsation is to be communicated.

Arranged to enter the cylinder at points to either side of the said pair or each pair of shoulders are ports or means of communication with the atmosphere and 'with an appropriate source of vacuum respectively such atniiospheric and vacuum ports being arranged to occur in alternate. sequence a direction lengthwise with the cylinder.

The term vacuum used in this specification includes any partialvacuum such as usually employed in milking machines. 'I The arrangement is such as the piston reciprocates the action of the shoulders off the latter in coming into and out ofabutment with those of the cylinderwill place the said pulsation ports in communication with the said atmospheric and: vacuum ports al? ternately thereby producing the secondary pulsation. i

The device may be arranged either to pro' duce a single cycle of pulsations or to produce a differential or double cycle off-pulsa;- tions that is to say one in. which' two pulsation ports or sets of ports are employed and in which one of` such pulsation ports orsets of ports is in communication with atmosphere at the moment the otherv pulsation port or set of ports is in communication vwith vacuum, a method sometimes employedy in claw pulsators in order that the 'teat-cups may be pulsated' in pairs. i For the purpose of producing the said reciprocal movement of the piston, there is providedA a chamber having a portion connectable to vacuum, a second portion under atmospheric or approximately atmospheric pressure, and a third portion connecta'ble to the primary pulsation. A Arranged within the said chamber and operatively connected with the said piston are a pair of diaphragms, one of which' constitutes a yieldable partition between, the said vacuum and atmospheric portions while the other diaphragm, which is of relatively greater effective area` constitutesA a, yieldable partition between one of the said portions and the primary pulsation portion.

The arrangement is such that the diference of pressure at the two sides of-v the smaller diaphragm tends to cause the latter to operate the piston constantly lin one 'di-y rection. At one period of theprim'ary pulsation the other or larger' diaphragm is also subject to difference in pressure tending to cause it to operate the piston in the` opposite direction to 'that of the aforismen-i tioned tendency of the other or smaller diaphragm. The relative areas of the two diaphragme are such that under the above mentioned conditions the larger diaphragm will prevail and operate the piston against the tendency of the smaller diaphragm. During the other period ot the primary pulsation however the pressures at the two sides of the larger diaphragm will be equal or approximately so thus rendering such diaphragm'incapable'of effectively opposing the smaller diaphragm which will in consequence operate the piston in the other or reverse direction. In this manner the combined operation of the two diaphragms will produce reciprocal movement of the piston in step with the primary pulsation.

In order that the nature ot the invention and its construction may be clearly understood, it will now be particularly described with reference to the accompanying drawings in which Fig. 1 is a plan view of a claw-pulsator constructed in accordance with the present invention, and adapted to provide a differential or double cycle of pulsations.

Fig. 2 is a sectional elevation of the same along the line A-B Fig. 1. the piston being shown in its midstroke position, and,

Fig. 8 is a view of the central portion of the cylinder turned axially round to a position at right angles with that shown in Fig. 2, the front portion being shown broken away in order to illustrate the positions oi the pulsation ports.

1 is a chamber having tour nipples 2, 3, 4. and 5 to receive the connections of the milk- Vchambers of' the four teat-cups of the set,

such chamber 1 being adapted to provide the necessary communication between the said connections and the milk-pipe 6 in a similar manner to that of certain constructions previously employed,

According to the present invention upon the necessary cover S oit the chamber 1 is carried a vertically disposed cylinder or housing 9 which is so bored as to provide four shoulders, viz, 10, 11, 12 and 1?), which shoulders are arranged in opposed pairs as shown.

Communicating with the bore ot the cylinder'between the pair ot shoulders 10 and 11 are two ports 14; and 15 constituting the entrance to nipples 16 and 1T respectively and by means of which nipples sec- Y ondary pulsations are communicated to the usual flexible connections of the pulsation chambers of two of the tcat cups ol" thc set.

Similarly, communicating with the bore of the cylinder between the pair of shoul.

ders 12 and 13 are two ports 18 and 19 constituting the entrances of two nipples 2O and 21 respectively and by means ot which nipples secondary pulsations are communi cated. t0 the usual flexible Connections of the pulsation chambers of the two remain- Y der and the atmosphere, while at a point y between the shoulders 11 and 12 is provided a port 23 communicating between the bore i of the cylinder and a source ot vacuum.

As here shown this vacuum connection is provided by means of a nipple 24 communi eating with the port 23 and so connected by means of a flexible connection 25 with a nipple 26 communicating with the chant ber 1. f

Adapted to reciprocate within the cylinder 9 is a piston 27, which fits loosely or with a. certain amount ot clearance within the portion of such cylinder extending between the various ports Ialcove mentioned and which piston is provided. with two peripheral flanges one of which 28 lies between the shoulders 10 and 11 while the other flange 29 lies between the shoulders 12 and 13.

The upper and lower surfaces of the flange 28 constitute an opposed pair of shouldersv adapted to come into and out ot abutment with the shoulders 10 and 11 respectively and similarly the upper and lower surfaces oit the 'Flange 29 constitute an opposed pair oli shoulders adapted to come into and out ot abutment with the shoulders 12- and 13 respectively.

The arrangement is such that when tlt. piston is at the upper end ot its stroke the upper shoulder ot the vfiange 28 will be in abutment with the shoulder 10 while Ythe lower shoulder ot the saidt1ange 28 will be clear ot the shoulder 11, the pulsation ports 141A and 15 will therefore be cut off from communication with the upper air ports 22 and placed. in communication with the vacuum port 23. ln this position of the piston also the upper shoulder of the flange 29 will be in abutment with the shoulder 12 while the lower shoulder of such V[iange 29 will loe clear ot the shoulder 13 thereby intercepting rommunication between the vacuum port 23 and the pulsation ports 18 and 19 and placing such pulsation ports in communication with Vthe lower air portsl 22.

llpon the piston moving tothe lower end ot its stroke the lower shoulder of the flange 28 will come into abutment with the shoulder 11 while the upper shoulder of such flange will be clear ot' the shoulder 10 thereby intercepting communication between the vacuum port 23 and the pulsation ports 14 and 15 and placing such pulsation ports in communication with the upper air ports 22. Simultaneously therewith the lower shoulder of the flange 29 will come into abutment with the shoulder 13, while the upper slunilder of such` flange 29 will be clear of the shoulder l2, thereby intercepting lcommunication between the lower air ports 22 and the pulsation ports 18 and 19 and placing pulsation ports in communication with the vacuum port ln this manner therefore the reciprocation ofthe piston will produce a differential or double cycle of pulsations.

It so desired the positions of the atmospheric and vacuum ports may be reversed, thatv is to say an atmospheric port may be substituted in place of the port 23 in which case two vacuum ports will be provided in place of the ports 22.

For the purpose of so actuating the pistou, the lower end of the latter is arranged to project downwardinto the chamber l in the upper portion of which are provided two diaphragms B() and 3l.

The central portions of the 'saidv diaphragms are attached tothe piston while their outer peripheries are attached to the walls ofthe chamber l in any suitable manner as by the provision of suitable seats or shoulders upon which the saidl peripheries are retained'by the action of the vacuum. The

chamber l is thus partitioned into three por-V tions, viz` a lower portion beneath the diaphragm 3l andv which portion is under continuous vacuum, an intermediate portion between the two diaphragms maintained under atmospheric pressure or approximately so as by means of openings or vents 32 communi.- cating between lsuch portion of the chamber and the atmosphere, and an upper portion above the diaphragm 30 to which portion is communicated the primary pulsation, as by means of the nipple 33.

The arrangement is such that the diaphragm Sl constituting apartition between the continuous vacuum of the lower portion of the chamber l and the atmospheric pressure of the intermediate portion, will tend continually to draw. the piston downward tov the lower end of its stroke. During the atmospheric orihigh pressure period of' the primary |mlsation the pressures above and below the'diaphragin 20 will be lequal or approximately so and consequently such dia.- phragm will be incapable of" effectively opposing the said tendency of the lower diaphragm 3l which latter will therefore cause the piston to perform its downstroke.

During the vacuum or low pressure period ofthe primary pulsation however the diaphragm 30 being under vacuum at its upper side and atmospheric pressureat its lower, will exert an upward pressure upon the piston and so cause the latter to perform its upward stroke against the tendency of the diaphragm Bl.

In order that it may perform this action the diaphragm 30 is made of the requiredl relatively greater effective area than the diaphragm. 31.

In construction'the diaphragme 30 and' 31 may be composed of thin sheet metal or other flexible material.`

In the preferred form of the construction however, as, here shown, such diaphragms each consist of a central rigid plate or disc provided around its periphery with an annular portion of rubber or other like flexible material adapted to make an air-tight joint with such disc and with the wall of the containing chamber. l

By this construction the yielding or flexible nature of the rubber will not only permit the required movements of the discs in response to the primary pulsation but will also allow such-dises sufficient freedoml in a radial direction to find their correct positions and thusV avoid any tendency on the part of such discs to throw the piston out of alinement with'the cylinder.

In the preferred form of the construction also as here shown the said annular rubbers are united by a web 34' formed integral with such rubbers while the rigid discs are also united: by a boss 35 and! by means of which boss the diaphragms are attached to the piston. y

As a modification of the arrangement of the chamber l `the positions of the atmospheric andk vacuum portions of such chamberl mayl be reversed, that' is `to say the portion beneath the diaphragm 3l will be under atmospheric or approximately atmospheric pressure in which case the portion between the two diaphragms 3() and:` 3l will be in communication vwith vacuum. ln this arrangement of the construction, the diaphragm 3l will tend to carry the piston upward; VDur-ing thevacuum period of the primary pulsation conditions above and below the diaphragm 30 will be equalV or approximately so and consequently such diaphragm will offer no effective opposition to the upward* movement of the piston under the said tendency of the diaphragm 3l. During the atmospheric or pressure lperiod of the primaryl pulsation however, the diaphragm 30 being under vacuum at its lower side and' atmospheric pressure at yits upperV side will exert a downward'` pressure upon the piston and so carry the latter tothe l'ower end of'its stroke against the aforesaid upward tendency of the diaphragm 31;

ln the case of a claw pulsator orother pulsator in whichthe diaphragme are contained" in a portion of a chamber connected with the milk-pipe, it would be necessary in the case of the last-described construction to provide a wall or partition to separate the atmospheric portion of such chamber imme-" diatfelybeneaththe'diaphragm 31 -from the lower or remainingl portion which is necessarily under'vacuum. For this reason the. first describedform of the invention is considered; preferable altl-'iough an equally etfec-= tive reciprocation of the piston can be obshoulder 10, and a lower portion containing the shoulder 13.

F or the purpose of clamping or securing4 the said parts together a screw 36 is provided and arranged to extend upward through the chamber l and through an aX- ial bore in the piston to the top portion of the cylinder where it is received within a suitably tapped hole 37.

The foregoing description is given in order to clearly explain the construction and operation of the invention which is however applicable not only to a claw pulsator but also to any pulsator employed for the purpose of producing a secondary pulsation or pulsations in any portion of a milking machine plant.

Thus for example the construction may be applied to a milk-bucket where such is employed in which case the construction may be similar to that already described except for the fact that the upper portion of such bucket may take the place of the chamber l.

Again the device may be employed as a relay or intermediate pulsator adapted to be inserted in any desired portion of the pulsation line, in which case in lieu of the chamber l, a special chamber or housing will be provided to contain the diaphragms 30 and 31.

A similar construction will be employed also in cases where the pulsator is used to operate a milk-releaser.

In cases where the pulsator is designed to supply a single cycle of secondary pulsations, as in the case of a relay or releaser pulsator, the cylinder will be provided with a -single pair of opposed shoulders and with which are adapted to co-act a single pair of opposed shoulders formed upon the piston.

claim.:

l. The combination with a milking machine including a source of vacuum, a source of primary pulsation, and apparatus adapted to receive secondary pulsations, of a secondary pulsator operable in response to said primary pulsation and adapted to produce said secondary pulsations comprising a chamber having a portion connected with vacuum, a secondportion under 'approximatelyatmospheric pressure, and a third portion con- .nected with the primary pulsation, a diaphragm in said chamber constituting a yieldable. artition between said vacuum and atmosp eric portions, A a second diaphragm therein of relatively greater effective area constituting a yieldable partition between one of said portions and saidprimary pulsation portion, and valve-means positively f connected with both of said diaphragms so as to be mechanically operated thereby and adapted when so operated to place aforesaid l ciprocal movement under the combined influences of vacuum, of approximately atmospheric pressure, and of the primary pulsation, a valve-housing mounted upon said chamber, an operable valve-member therein positively connected with both of said diaphragms so as to be reciprocated thereby, ports connecting with vacuum and with atmosphere spaced longitudinally in said housing, means of communication with aforesaid secondary pulsation receiving apparatus located between said vacuum and atmospheric ports, opposed peripheral shoulders around the interior of said housing and located between said means of communication and said vacuum and atmospheric ports, and corresponding opposed peripheral shoulders formed upon said operable valve-member adapted when the latter is reciprocated to come into and out of abutment with said shoulders of the housing thereby connecting said means of communication with vacuum and atmosphere alternately.

3. The combination withA a milkimg'ma-V of vacuum,

andi

including a source of primary pulsation,

chine a. source a plurality of two-chamber teat-cups,-

of a pulsator operable in response to said primary pulsation and adapted to produce a differential secondary pulsation in the pulsation chambers of said teat-cups and comprising a chamber, a pair of diaphragms therein adapted to reciprocal' movement under the combined influence of vacuum. of approximately atmospheric pressure, and of the primary pulsation, a valve-housing mounted upon said chamber, an operable valve-member in said housing positively connected with both of said diaphragme so as to .be reciprocated thereby, ports communicating with the atmosphere and with vacuum spaced in alternate sequence longitudinally in said housing, a plurality of secondary pulsation ports located between said atmospheric and vacuum ports certain of such pulsation ports being connected to the pulsation chambers of certain of said teatcups and the remainder of such pulsation ports being connected to the pulsation chambers oi' the remainder of said teat-cups, opposed pairs of peripheral shoulders around the interior of said housing separating said pulsation ports from the adjacent vacuum and atmospheric ports in each case, and corresponding opposed pairs or' peripheral shoulders formed upon said operable valve member, one shoulder of each pair upon said member being adapted to abut with one shoulder of each pair upon said housing when said member is in one extreme position thereby placing certain of said pulsation ports in communication with vacuum and the remainder of such pulsation ports in communication with atmosphere while the remaining shoulders of said member are adapted to similarly abut with the remaining shoulders of the housing when said member' is in its other extreme position thereby reversing suoli connections of the pulsation ports.

4L. The combination with a milking machine including a source of vacuum, a source of primary piilsation, and apparatus adapted to receive secondary pulsations, of a secondary pulsator operable in response to said primary pulsation and adapted to produce said secondary pulsations comprising a chamber having a portion connected with vacuum a second portion under approximately atmospheric pressure, and a third portion connected with the primary pulsation, a diaphragm constituting a yieldable partition between said vacuum and atmospheric portions, a second diaphragm of relatively greater effective area constituting a yieldable partition between one of said portions and said primary pulsation portion, each of said diaphragms consisting of a flexible annular portion connecting with the Wall of said chamber 1and a central rigid portion connected with said annular portion,l and valve-means positively connected .with said rigid portions of both of said diaphragms so as to be mechanically actuated thereby and adapted when so operated to place aforesaid secondary pulsation receiving apparatus in communication With vacuum and atmosphere alternately.

5. The combination with a milking machine including a source of vacuum, a source of primary pulsation and apparatus adapted to lreceive secondary pulsations, oi a secondary pulsator operable in response to said primary pulsation and adapted to produce said secondary pulsations comprising a chamber, a pair of diaphragms therein adapted to reciprocal movement under the combined influence of vacuum, of approximately atmospheric pressure, and of the primary pulsation, a cover for said chamber, a valve housing upon said cover and having connections to atmosphere, to vacuum, and to said secondary pulsation, receiving apparatus, a valve member' within said housing reciprocal by said diaphragms and adapted to co-act with said housing to place said secondary pulsation receiving apparatus in communication with atmosphere and vacuum alternately, and a screw extending through said chamber and through an axial bore in said operable valve-member and whereby said chamber, its cover and valvehousing are secured together.

In testimony whereof I have signed my naine to this specification.

ROBERT BRUCE FORSYTH.

Vitnesses':

CYRIL CARLYN CORBIN, KATHLEEN DWYLLis KING. 

